Abstract
A decrease in the filled grain ratio (FGR) under high nitrogen (N) conditions inhibits the increase in rice yield in the tropical highlands of equatorial East Africa. We hypothesized that, under high N fertilization, the decrease in FGR is due to low temperatures during the reproductive growth stages, and that high grain yield can be achieved using cold tolerant varieties. Two cold-susceptible varieties (BW196 and Komboka) and a cold-tolerant variety (NERICA 1) were grown under 57, 114, and 171 kg N ha−1 of N fertilization. Grain yield increased with a higher N fertilization rate only in NERICA 1. Shoot dry weight and total spikelet number increased in all varieties under high N conditions. Although FGR decreased with increases in N fertilization rate in all varieties, the adverse effects of high N fertilization on FGR were least observed in NERICA 1. However, temperature did not affect FGR in all N treatments, growth stages, and varieties, except for Komboka during the ripening stage under high N conditions. The findings did not support the hypothesis that high-N-induced decreases in FGR are due to low temperatures. High-N-induced decreases in FGR in Komboka were mainly attributable to the poor filling of spikelets during the ripening stage due to excess total spikelets. Factors other than filling high-N-promoted increases in total spikelet number may affect FGR in BW196 and NERICA 1 under high N conditions in Mwea.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Rice grain yield increased with a higher N fertilization rate only in NERICA 1.
- Taxon
- Rice
Oryza sativat0 - Material
- NERICA 1e0
- Treatment
- higher N fertilization ratee0
- Outcome
- Grain yielde0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Grain yield increased with a higher N fertilization rate only in NERICA 1”
t0“Rice Varieties”
Claim · model-written summary
Shoot dry weight and total spikelet number increased in all rice varieties under high N conditions.
- Taxon
- RiceOryza sativat0
- Treatment
- high N conditionse0
- Outcome
- Shoot dry weight and total spikelet numbere0
- Direction
- increasede0
- Qualifier
- all varietiese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Shoot dry weight and total spikelet number increased in all varieties under high N conditions”
t0“Rice Varieties”
Claim · model-written summary
Filled grain ratio decreased with increasing N fertilization rate in all rice varieties.
- Taxon
- RiceOryza sativat0
- Treatment
- N fertilization ratee0
- Outcome
- FGRe0
- Direction
- decreasede0
- Qualifier
- all varietiese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“FGR decreased with increases in N fertilization rate in all varieties”
t0“Rice Varieties”
Claim · model-written summary
The adverse effect of high N fertilization on filled grain ratio was least observed in NERICA 1.
- Taxon
- RiceOryza sativat0
- Material
- NERICA 1e0
- Treatment
- high N fertilizatione0
- Outcome
- adverse effects of high N fertilization on FGRe0
- Direction
- least observede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the adverse effects of high N fertilization on FGR were least observed in NERICA 1”
t0“Rice Varieties”
Claim · model-written summary
Temperature did not affect filled grain ratio in any N treatment, growth stage or variety, with the exception noted for Komboka.
- Taxon
- RiceOryza sativat0
- Treatment
- temperaturee0
- Outcome
- FGRe0
- Direction
- did not affecte0
- Qualifier
- all N treatments, growth stages, and varietiese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“temperature did not affect FGR in all N treatments, growth stages, and varieties, except for Komboka during the ripening stage under high N conditions”
t0“Rice Varieties”
Claim · model-written summary
For Komboka during the ripening stage under high N conditions, temperature did affect filled grain ratio.
- Taxon
- RiceOryza sativat0
- Material
- Kombokae0
- Organ / stage
- ripening stagee0
- Treatment
- temperaturee0
- Outcome
- FGRe0
- Qualifier
- high N conditionse0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“temperature did not affect FGR in all N treatments, growth stages, and varieties, except for Komboka during the ripening stage under high N conditions”
t0“Rice Varieties”
Claim · model-written summary
The high-N-induced decrease in filled grain ratio in Komboka was mainly attributed to poor spikelet filling during ripening due to excess total spikelets.
- Taxon
- RiceOryza sativat0
- Material
- Kombokae0
- Organ / stage
- ripening stagee0
- Outcome
- High-N-induced decreases in FGRe0
- Qualifier
- poor filling of spikelets during the ripening stage due to excess total spikeletse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High-N-induced decreases in FGR in Komboka were mainly attributable to the poor filling of spikelets during the ripening stage due to excess total spikelets”
t0“Rice Varieties”
Claim · model-written summary
Factors other than filling of the high-N-promoted increase in total spikelet number may affect filled grain ratio in BW196 and NERICA 1 under high N conditions.
- Taxon
- RiceOryza sativat0
- Material
- BW196 and NERICA 1e0
- Treatment
- high N conditionse0
- Outcome
- FGRe0
- Qualifier
- Factors other than filling high-N-promoted increases in total spikelet numbere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Factors other than filling high-N-promoted increases in total spikelet number may affect FGR in BW196 and NERICA 1 under high N conditions”
t0“Rice Varieties”
The same questions in other papers
nitrogen · growth · Oryza sativa (rice)Positive and negative results
401 papers in the same direction as this paper · 101 in the opposite direction · 8 reporting no difference from an alternative
- negative
- negative
- negative
507 papers more in this group
See all 511 papers →fertilization · yield · Oryza sativa (rice)Positive and negative results
3,182 papers in the same direction as this paper · 207 in the opposite direction · 65 reporting no difference from an alternative
- no effect
- no effect
- negative
3,451 papers more in this group
See all 3,455 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.